native email app problem...

Recently I switch my iphone 5 for another because I had a problem with the first one. I did the whole thing using icloud. In other words I got all my information in the phone with the help of icloud. My only problem is the native email app. I want my icloud email address back but I can't use it. Every time I try to use my email, ios tell me I have to configure it but when I try to log in to email part it says that the email account is already added. "This icloud account has already been added to your iphone" but I can't use it at all.
Any ideas on how to fix this little problem and go back to normal??